Prenatal alcohol exposure causes a variety of morphological and behavioral abnormalities. Similarities between these effects in humans and those found using animal models are striking, supporting the usefulness of pursuing animal studies. Recently, a rodent model using neonatal administration of ethanol has been used to study the effects of alcohol exposure during the period of development equivalent to the third trimester of human pregnancy. The findings from this research have demonstrated morphological changes in the central nervous system that are more severe than those seen following prenatal alcohol exposure in the rat. These morphological alterations (e.g. hippocampal anomalies) are thought to underlie some of the behavioral effects resulting from alcohol exposure. Thus, exposure to alcohol late in the development of the central nervous system could be more detrimental to normal behavioral maturation than earlier exposure. Our aim is to investigate the behavioral teratogenicity of neonatal ethanol exposure in rats using tasks previously shown to reveal deficits following prenatal exposure, as well as tasks which have been shown to be sensitive to changes in postnatal neural development. Animal will be fed varying concentrations of ethanol (0%, 2.8% and 3.5%) in isocaloric liquid diets via intragastric cannulae. The animals will be tested at varying ages for differences in activity, reactivity, and exploratory behavior, performance on several learning tasks, and coordination, gait, and balance. These tasks should provide an assessment of the integrity of the limbic system and the cerebellum. In summary, our studies should provide a better understanding of the contribution of neonatal exposure to ethanol to the development of behavioral dysfunction in rats and could have important implications for the effects of exposing human fetuses to alcohol during the third trimester of pregnancy.